Okay, so, first, my issues with the app were:
- after downloading a playlist, some time later when trying to play it offline it suddenly appeared as not downloaded (very frustrating)
- local files not synching
- tracks not showing up in app
- general frustration with about every single feature
If you experience some of these issues, I bet you have a lot of playlists. Like 100, or more.
Well, guess what, if you trim down your playlists to about 20 or 30 (I'm on 20 now) the app will suddenly become fully functional. So yeah, try that. I know deleting many playlists is a painful proccess, but at least now I have my music on my cell phone. Plus I cleaned up my account after deleting playlists I didn't listen in years.
Apparently this app has a hard time when it comes to big amounts of playlists. Devs please take note and fix this asap.
Hope this helps someone!